For metal silicide (e.g., titanium silicide) integration schemes, metal (e.g., titanium) and/or metal nitride (e.g., titanium nitride) films are deposited on clean substrate (e.g., silicon) surfaces and annealed to form metal silicide (e.g., TiSi) films. After deposition of a metal film, metal silicide film, and/or metal nitride film, an air break or oxygen exposure may occur prior to annealing. The metal nitride film becomes oxidized and the contact resistance increases. There is a need for methods to reduce oxygen in post-annealed oxidized metal nitride films. There is also a need for methods of reducing resistivity of oxidized annealed metal nitride films to improve contact resistance.